I think you bought OEM discs. These discs come with a whole lot of crap included (slipstreamed). The problem is that most of these included things do not work on a MAC at all.
First of all your Mac Book pro needs to have an Intel cpu, otherwise the XP installation will fail. Then you require a very normal Windows XP setup disc. A retail one, not an OEM one. Booting should go without problems. You just insert the disc and bootcamp should do the rest.
Although there actually IS a normal XP SP3 disc available, i suggest getting a normal SP2 XP disc, because bootcamp has not been updated that well in the last year. It's not a big problem since you can download SP3 and all included patches straight from the windowsupdate website.
After that, you have a working XP and you will need to install the bootcamp drivers. The best drivers are at apple.com.
If this all fails, i suggest removing all the bootcamp partitions and give the free data back to the MAC OS, then go to VMWARE.com and get the vmware player. Or the virtualbox at virtualbox.org. This way you can run almost any Operating System within Mac OS.